Electrical interconnects for transferring charge from one member to another member or for carrying and transferring current from one member to another are found in a wide range of fields and applications. For example, printing and copying processes require the transfer of electrical charge to perform many operations, e.g., development, transfer and cleaning operations. Thus, printing and copying devices use electrical contacts to transfer electrical charge and current to perform these operations.
For example, a specific member, e.g., a photoconductive member, is electrically charged by transferring an electrical charge from a first member to the photoconductive member. A contact, e.g., a sliding contact, may be used as the specific member to bias, i.e., to transfer an electrical charge to, the photoconductive member. For example, U.S. Pat. No. 5,887,225 to Bell, the disclosure of which is incorporated herein by reference in its entirety, discloses a charge transfer device that is in electrical contact with the end shafts of a first and second developer roll of a copier through a sliding electrical contact. The charge transfer device electrically biases the rolls by transferring an electrical charge from a voltage source to the end shafts of the developer rolls via the sliding electrical contact. Other methods of transferring an electrical charge either to or from a member include placing the member to be biased in rubbing contact with a stationary brush, a flexible electrically conductive sheet, or a metal strip.
U.S. Pat. No. 6,444,102 to Tucci discloses an electrical contact fabricated in narrow strips that can be around 0.010 to 0.015 inches in thickness. In Tucci, the electrical contact is formed of carbon fibers fused or conductively bonded together and fixed to a carrier. In Bell, the electrical contact is formed of a polymer composite of multiple electrically conductive carbon fibers.
An example of a carbon fiber polymer composite is known by the trade name CarbonConX™. CarbonConX™ includes a high concentration (e.g., >40% weight) of electrically conductive, high strength, continuous carbon fiber tow (or optionally, metalized carbon fiber tow) compounded within a selected host polymer matrix. A tow is defined as a unit of fiber volume where many fibers, for example from a dozen or more to many thousands made from carbon or metalized carbon, are arranged in a generally parallel array. The individual fibers may have a thin surface layer of a suitable polymer coating referred to as sizing, for example a epoxy monomer or polyvinyl pyrollodone (PVP), which serves to facilitate bonding of the fiber to the selected host polymer or to facilitate handling of the fibers during the various manufacturing and compositing processes. Carbon fiber polymer composites may be used as an alternative to metal contacts or traditional conductive plastics in devices for electrostatic discharge applications as well as other application areas, such as sensor components, moving rotational contacts, motors, electrical switch components, etc. Because carbon is generally non-reactive and less susceptible to corrosion when compared to other materials, such as, e.g., metal, carbon fiber has advantages over metal and may be used in harsh or corrosive environments, including saltwater, nuclear power environments, space, medical, and biological fields.
Applying pultrusion methods to produce the carbon fiber composites enables high strength to be obtained and allows many forms of the carbon fiber to be manufactured into various design shapes and configurations, such as, solid rods, tubes, and thin flat sheets. Moreover, the carbon fibers or metalized carbon fibers used in carbon fiber polymer composites are considered, generally, to be of high electrical conductivity as well as high strength and capable of providing statistically regular and evenly distributed electrical contact sites for charge conduction across an interface.